Portfolio Statistics

Portfolio Structure
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Credit Quality
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Important Characteristics Information

Portfolio characteristic data are based on unaudited net assets.

The portfolio is actively managed, and current holdings may be different.

For all securities other than those specifically described below, ratings are assigned to underlying securities utilizing ratings from Moody’s, Fitch, and Standard & Poor’s rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change. U.S. Government includes securities issued by the U.S. Department of the Treasury. Federal Agencies includes rated and unrated U.S. Agency fixed-income securities, U.S. Agency MBS, and CMOs of U.S. Agency MBS. Other Not Rated includes fixed income securities which have not been rated by any rating agency. The portfolio itself has not been rated.

Portfolio characteristics are based on equivalent exposure, which measures how a portfolio's value would change due to price changes in an asset held either directly or, in the case of a derivative contract, indirectly. The market value of the holding may differ.

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Cash and other assets are less liabilities; this may include derivative offsets.

Definitions

Alpha: Alpha is a measure of the portfolio's risk-adjusted performance. When compared to the portfolio's beta, a positive alpha indicates better-than-expected portfolio performance and a negative alpha worse-than-expected portfolio performance.

Average Coupon: Average Coupon is the equivalent exposure weighted coupon of all interest bearing instruments as a percent of the total equivalent exposure of all fixed income holdings, including short term and interest rate derivatives which have coupons. Coupons are netted for securities with a payable and receivable leg. Non-accruing securities are treated as having a coupon equal to zero.

Average Effective Duration: Average Effective Duration is a measure of how much a bond’s price is likely to fluctuate with general changes in interest rates, e.g., if rates rise 1.00%, a bond with a 5-year duration is likely to lose about 5.00% of its value.

Average Effective Maturity: Average effective maturity is a weighted average of maturity of the bonds held in a portfolio, taking into account any prepayments, puts, and adjustable coupons which may shorten the maturity. Longer-maturity funds are generally considered more interest-rate sensitive than shorter maturity funds.

Beta: Beta is a measure of the volatility of a portfolio relative to the overall market. A beta less than 1.0 indicates lower risk than the market; a beta greater than 1.0 indicates higher risk than the market. It is most reliable as a risk measure when the return fluctuations of the portfolio are highly correlated with the return fluctuations of the index chosen to represent the market.

Credit Quality: For all securities other than those specifically described below, ratings are assigned to underlying securities utilizing ratings from Moody's, Fitch, and Standard & Poor's rating agencies and applying the following hierarchy: If all three agencies provide a rating, the middle rating (after dropping the highest and lowest ratings) is assigned; if two of the three agencies rate a security, the lower of the two is assigned. Ratings are shown in the S&P and Fitch scale (e.g., AAA). All ratings are subject to change. U.S. Government includes securities issued by the U.S. Department of the Treasury. Federal Agencies includes rated and unrated U.S. Agency fixed-income securities, U.S. Agency MBS, and CMOs of U.S. Agency MBS. Other Not Rated includes fixed income securities which have not been rated by any rating agency. The fund itself has not been rated.

Information Ratio: Information ratio is a measure of consistency in excess return. The annualized excess return over a benchmark divided by the annualized standard deviation of excess return.

R-squared: R2 represents the percentage of the portfolio's movements that can be explained by the general movements of the market. Index portfolios will tend to have values very close to 100

Sharpe Ratio: The Sharpe Ratio is a risk-adjusted measure calculated to determine reward per unit of risk. It uses a standard deviation and excess return. The higher the Sharpe Ratio, the better the portfolio's historical risk-adjusted performance.

Standard Deviation: Standard deviation is an indicator of the portfolio's total return volatility, which is based on a minimum of 36 monthly returns. The larger the portfolio's standard deviation, the greater the portfolio's volatility.

Tracking Error: Tracking error is the active risk of the portfolio that measures the dispersion of the portfolio's return minus the benchmark's annualized return.

Treynor Ratio: Treynor Ratio is a risk adjusted measure of performance. It is the ratio of the annualized excess return of the portfolio over the risk free rate for a given period divided by the Beta of the portfolio versus its benchmark for the same period. It measures the amount of excess return over the risk free rate earned per unit of systematic risk (beta) assumed.

Upside / Downside Capture %: The upside and downside capture is a measure of how well a manager was able to replicate or improve on phases of positive benchmark returns, and how badly the manager was affected by phases of negative benchmark returns. To calculate the up capture, we first form new series from the manager and benchmark series by dropping all time periods where the benchmark return is zero or negative. The up capture is then the quotient of the annualized return of the resulting manager series, divided by the annualized return of the resulting benchmark series. The down capture is calculated analogously.

Yield to Worst: The weighted average yield-to-worst of all portfolio holdings. The yield-to-worst is computed by using the lower of either yield-to-maturity or the yield-to-call on every possible call date. Essentially the yield-to-worst is a bond's yield-to-maturity under the least desirable bond repayment pattern under the assumption that bond market yields are unchanged.

This publication is authorized for distribution only when preceded or accompanied by a prospectus, or summary prospectus, for the portfolio being offered. Consider the fund's investment objectives, risks, charges and expenses. Contact MFS or view online. Read it carefully.